Medline ® Abstracts for References 29,30
of 'Overview of vasectomy'
Vasectomy and the incidence of testicular cancer.
Strader CH, Weiss NS, Daling JR
Am J Epidemiol. 1988;128(1):56.
Adult male residents of 13 counties of western Washington state in whom testicular cancer had been diagnosed during 1977-1983 (n = 333) were interviewed over the telephone regarding their history of genital tract conditions, including vasectomy. For comparison, the same interview was given to a sample of 729 men selected from the population of these counties by dialing telephone numbers at random. A higher proportion of cases than controls reported having had a vasectomy (relative risk = 1.5, 95 per cent confidence interval = 1.0-2.2). However, the association was restricted entirely to Catholic men. Whereas a history of vasectomy was reported with approximately equal frequency by Catholic and non-Catholic cases, only 6.3 per cent of Catholic controls reported such a history in contrast to 19.7 per cent of other controls. While the authors cannot rule out the possibility that there is a true difference of the effect of vasectomy on the incidence of testicular cancer as a function of religion, it seems more plausible that selective underreporting by Catholic controls has produced a spurious relation.
Hanford Environmental Health Foundation, Richland, WA.
Influence of antisperm antibodies on human sperm function.
Aitken RJ, Parslow JM, Hargreave TB, Hendry WF
Br J Urol. 1988;62(4):367.
Antisperm antibodies have been found in about 8% of men with infertility and in 60 to 80% of patients following vasectomy. In order to investigate the way antibodies influence sperm function we studied serum and seminal plasma from patients with infertility (n = 61) or undergoing vasovasostomy (n = 25). These antisera were characterised to determine their TAT titre, the nature of the target antigens and their capacity to interfere directly with fertilisation. The results indicate that antibodies from both groups of patients exhibit a capacity to stimulate or suppress sperm/oocyte fusion. The proportion of samples showing stimulatory activity was higher (50%) in the vasovasostomised population than in patients with infertility (21%). The remainder of the antisera suppressed sperm/oocyte fusion. There was no correlation between the titre of antisperm antibodies and their capacity to influence sperm function, indicating that it is the nature of the target antigens which is of significance rather than the antibody concentration. Western blot analysis indicated that these antisera targeted a group of sperm surface antigens with molecular weights of 30kD (35,45,66,90 and 115kD). Monoclonal antibodies are now being prepared in order to determine which of these specific components are involved in the suppression of sperm function.
MRC Reproductive Biology Unit, Edinburgh.